mtx: now the serial is sorted remove the polling
trs80: adjust link map to make more sense
trs80: Add a tool to build the needed jv3 images
trs80: update config.h
trs80,floppy: bug fixes noticed in passing
process: flag a tiny race

I think we can just remove the restore, but needs checking over
trs80: move udata and program top

Matches the linker and allows for the fact that F400-FFFF is occupied by
the keyboard mmio and the video map
trs80load: TRS80 loader

Assumes single sided double density disk. Sets up the memory map, moves itself
to 0x00-0xff and then loads the kernel at 0x100 before running it.